Liddle Hart was born today - English military historian and theorist was born in Paris on October 31, 1895. Served as an officer in the British Army in World War I, witnessed trench warfare. He participated in the Battle of the Somme and was recognized for his bravery. Over the next few years, he pondered the reasons for the heavy loss of life and developed the principles underlying good strategy, principles which he said had been ignored by all the military leaders of the First World War. Liddle Hart argued that a rigid strategy of strong direct attacks or fixed defensive positions should not be adopted. Instead, mobile units should be used, moving and operating according to the doctrine of indirect action.